Float valve for refrigerating systems



April 17, 1934.

' c z. STEENSTRUP FLOAT VALVE FOR REFRIGERATING SYSTEMS Filed Nov. 5. 1932 Inventor": Christian Steenstrup,

His Armor-neg.

Patented Apr. 17, 1934 UNITED STATES FLOAT VALVE FOR REFRIGERATING SYSTEMS Christian Steenstrup,

Schenectady, N. Y., as-

- .signor to General Electric Company, a corporation 01" New York Application November 5, 1932, Serial No. 641,396

9 Claims.

My invention relates to refrigerating machines and particularly to refrigerating machines of the type having a valve, or flow controlling device for the purpose of admitting-refrigerant to the low pressure side of the system from the high pressure side thereof.

In connection with refrigerating systems adapted to cool a compartment, such as a domestic refrigeratonan evaporator which is supplied with refrigerant from some external source is ordinarily placed within the compartment. It is necessary to provide a device for controlling the flow of refrigerant to the evaporator, such as a valve or the like which maintains the neces sary difference of pressure between the evaporator and the source of refrigerant supply. When the refrigerant passes from the high pressure to the low pressure side of this flow controlling device, a portion of the refrigerant vaporizes due to the sudden change in pressure which absorbs heat and reduces the temperature of the flow controlling device, so that it absorbs heat from the surrounding media and from the adjacent parts of the system.

An object of my invention is to utilize the refrigerating effect of the refrigerant expanded through the flow controlling device to cool the refrigerator compartment, and in this way to decrease the losses in the system.

Another object of my invention is to provide a flow controlling device of the above character so arranged and constructed that heat flow thereto from the other parts of the refrigerating system which operate at a higher temperature is substantially prevented.

Another object of my invention is to provide a simplified float valve mechanism.

Further objects of my invention will appear as the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

In the accompanying drawing, Fig. 1 is a view in section of a float operated valve embodying my invention; Fig. 2 is a fragmentary perspective view of the valve lever mechanism shown in Fig. 1, and Fig. 3 is a side elevation of a refrigerator cabinet having a refrigerating system embodying my invention.

In Fig. 3 of the drawing I have shown my invention in connection with a refrigerating system which is arranged to cool an insulated refrigerator cabinet 10. The refrigerating system is 5 mounted in a removable insulated top wall 11 of the cabinet and includes a cooling unit or evapo- 'rator 12 attached to the inner wall of the top 11, which is arranged to cool the air in a refrigerator cabinet and make ice or freeze other articles placed therein. This system also includes a motor and compressor unit arranged within an enclosing casing 13 mounted on the removable top wall of the cabinet. The refrigerant vaporized in the evaporator 12 passes through a connection to the compressor within the casing 13 and the compressed refrigerant is discharged into the casing 13 from whence it passes through the connection 14 to the helical air cooled condenser coil 15 supported on cooling fins in spaced relation to the casing 13. The compressed refrigerant in passing through the condenser coil 15 is cooled and condensed into a liquid and then flows through the connection 16 into a float valve chamber 17 which is mounted in the insulated top 11 and extends into the insulation therein. The compressed refrigerant which is condensed into liquid in this way accumulates in the float valve chamber 17 and actuates a float therein to control the flow of liquid refrigerant through the connection 18 to the evaporator 12. This cycle of operation is continuously repeated during operation of the machine.

The particular construction of the float valve is shown in Fig. 1 and includes an inverted cupshaped receptacle 17a which is brazed or welded to a base 19. This receptacle is welded, or otherwise secured, in a flanged opening in the top wall 20 as indicated at 21 and is embedded in the insulating material 22 arranged between the upper wall 20 and the lower wall 23 of thetop 11. The valve 24 which controls the flow of liquid refrigerant from the float valve chamber 17a to the evaporator 12 is controlled by a float 25, which is slidably mounted on a guide-rod 26 supported within the casing 2511. This guide-rod is supported in a lower seat 27 and at the upper end thereof in a fitting 28 provided with a conical valve 29 which engages the upper end of the guide-rod to retain the same in place against the action of a spring 30. The spring 30 is retained under compression between the base 19 of the float valve chamber and retaining washer 31 which abuts a pin 32 extending through the guide-rod. During ordinary operation of the float valve the float 25 rises and falls in accordance with variations in the level of the liquid refrigerant in the float valve chamber, and the movement of this float is utilized to control the opening and closing of the valve 24 between the float valve chamber and the evaporator by providing a linkage connecting the float with the valve 24.

It will be understood that the float chamber 17a. is subject to the high temperature and pressure in the condenser 15 of the refrigerating system, and that the evaporator 12 is maintained at low temperature and pressure by the compressor, so that the liquid refrigerant in the evaparator is vaporized at the desired rate. As a result, when liquid refrigerant accumulates in the float chamber sufficiently to raise the float 2 5 and open the valve 24, a portion of the liquid refrigerant flowing into the connection below the valve suddenly vaporizes, because of the reduction in pressure to which it is subjected, and considerably lowers the temperature of the portions of the system in heat exchange relation therewith. In accordance with my invention the valve 24 is, therefore, arranged within the refrigerator cabinet 10, so that the evaporation of liquid refrigerant in passing through the valve seat will produce a useful refrigerating effect in the cabinet. Moreover, the connection between the seat of the valve 24 and the lever mechanism connecting the valve to the float 25 are made of a material of low thermal conductivity to prevent the conduction of heat from the comparatively warm cabinet walls and the parts of the float chamber to the valve, which would cause a loss in the capacity of the refrigerating system.

As shown in Fig. 1 of the drawing, the valve 24 cooperates with a seat 33 formed in a cylindrical plug 34 in the lower end of a tube 35 extending through the base 19 of the float valve chamber to which it is brazed or welded to form a gas-tight joint, and the tube 35 is made of a copper-nickel alloy sold under trade name of Monel metal, which is of low thermal conductivity. The cylindrical plug 34 is provided with a valve guide portion 36 with a diameter less than that of the conduit and main portion of theplug and having a cylindrical bore 3'7 therein in alignment with the valve seat 33 to guide the valve 24 toward and away from its seat and spaced from the inside of the tube 35 to provide for the flow of liquid refrigerant through the tube 35 to the valve seat 33, the portion 36 being cut away as indicated at 38 to provide for the flow of liquid refrigerant through the valve seat 33 when the valve 24 is retracted therefrom. The valve 24 is connected to the float 25 by a linkage which is also made of Monel metal. This linkage includes arms 39 connected by an integral crosspiece 40 and having rounded portions 41 arranged in opposite sides of a groove 42 formed in an extension 43 secured to the lower end of the float. The other ends of the arms 39 are fitted about a flattened portion 44 formed on the upper end of the tube 35 and each of the arms is provided with notches 45 in the ends thereof engaging a pin 46 secured in the upper end of the tube 35. The valve 24 is connected to the arms 39 by a link 47 of U-shaped cross-section, which is fitted over the upper end of the valve and pivotally secured thereto at 48 and to the arms 39 adjacent the pin 46 by a pin 49. The pin 49 extends through the link and the arms and through elongated openings 50 in the flattened upper end of the tube 35. By this arrangement the raising and lowering of the float 25 swings the arms 39 about the pin 46 and correspondingly raises and lowers the link 47, so as to open and close the valve 24. For convenience in assembling the linkage above described, the pin 49 is bent at right angles at 51, as shown in Fig. 2, and the end of the pin 46 is bent in the form of a U-shaped loop 52 about the end 51 of the pin 49. The end of the loop 52 is bent downwardly about a notch 53 in the upper end of the tube 35, so that the pins 46 and 49 are prevented from being displaced.

During operation of the mechanical refrigerating system shown' in the drawing, the liquid refrigerant supplied by condenser 15 accumulates within the float chamber 17a as it is liquefied. If the parts of the float valve are in the position shown in Fig. 1, the liquid refrigerant will accumulate until there is sufficient to raise the float 25, whereupon needle valve 24 is lifted and liquid refrigerant is admitted to conduit 18. As the liquid refrigerant passes through the valve it tends to expand and evaporate due to the drop in pressure so as to absorb heat. This will cool the valve seat and the surrounding plug including the valve guide portion. Since the liquid refrigerant must flow in a restricted space around the valve guide portion it will be pre-cooled before reaching the valve seat. This plug construction effects a highly efficient use of the cooling capacity produced upon expansion of refrigerant at the valve. As the tube 35 and the linkage connecting the float to the valve 24 are made of a material of low thermal conductivity, there will be substantially no conduction of heat from the float chamber and cabinet wall, so that loss of refrigerating capacity of the system will be minimized.

Although I have described and illustrated my "invention in connection with a float operated valve it will be understood that it is also useful in connection with other flow controlling devices. I do not, therefore, desire my invention to be limited to the particular arrangement shown and described, and I intend in the appended claims to cover all modifications within the spirit and scope of myinvention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A refrigerating system including a compartment to be cooled, heat absorbing means for said compartment, a flow controlling device, means for supplying refrigerant to said heat absorbing means through said flow controlling device, said fiow controlling device being heat insulated from said supply means, and means of low heat conductivity for conducting refrigerant from said supply means to said fiow controlling device;

2. A refrigerating system including a compartment to be cooled, an evaporator in said compartment, a valve arranged inside of said compartment, means for supplying refrigerant to said evaporator through said valve, said means including a float chamber having a float therein and arranged outside of said compartment, means utilizing the movement of said float for controlling said valve, and means of low heat conductivity for conducting refrigerant from said float chamber to said valve.

3. A refrigerating system including an insulated compartment to be cooled, an evaporator in said compartment, a flow controlling device in said compartment, means for supplying refrigerant to said evaporator through said flow controlling device, said means including a float chamber embedded in the insulation of said compartment and having a float therein, means utilizing the movement of said float for controlling said device, and means of low heat conduc- 4. A refrigerating system including a compartment to be cooled, an evaporator, a valve located lnteriorly of said compartment, means for supplying refrigerant to said evaporator through said valve, said means including a float chamber located outside of said compartment, a conduit for conducting refrigerant from said float chamber to said valve, and a linkage for utilizing the movement of said float for controlling said valve,

a portion of said linkage and said conduit being portion of said conduit for controlling said valve in accordance with the movement of said float, said conduit and said lever mechanism being made of a material of low heat conductivity.

6. A float operated valve including a chamber havinga float therein, a conduit having a flattened portion extending within said chamber, a valve in the end of said conduit remote from said chamber, a lever pivotally secured to said float and the flattened portion of said conduit, a link arranged within said conduit and connected to said valve and said lever, said conduit havin a slot accommodating the connection between said lever and said link so that the movement of said float can be transmitted through said link to said valve, said link and said conduit being made of a material of low heat conductivity.

'7. A float, operated valve for refrigerating systems incluuding a float chamber having afloat therein, a conduit extending within said chamber, means including a plug having av portion with a diameter less than that of said conduit and extending therein and a main portion with a diameter the same as that of said conduit for closing the end of said conduit, said main portion having a passage therethrough and communicating 1 with the interior of said conduit, means including a'valve for opening and closing said passage, and means including a'lever mechanism for controlling said valve in accordance with the movement of said float.

8. A float operated valve for refrigerating systems including. a float chamber having a float therein, a conduit extending within said chamber, means including a plug having a portion with a diameter less than that of said conduit and extending therein and a main portion with a diameter the same as that of said conduit for closing the end of said conduit, said main portion having a passage therethrough and communicating with the interior of said conduit, means including a valve for opening and closing said passage, and means including a lever mechanism for controlling said valve in accordance with the movement of said float, said conduitand a portion of said -lever mechanism being constructed of a material having low heat conductivity.

9. A float operated valve including a chamber having a float therein, a conduit having one end extending within said chamber and having a portion of said end cut away, the sides of the remaining portion of said end of said conduit being extended inwardly, ,a link pivotally connected to the end of said conduit within said chamber and to said float, a valve in the end of said conduit remote from said chamber, and means including a link connecting said valve and said first named link and arranged between said inwardly extended sides of said conduit for actuating said valve in response to themovement of said float.

CHRISTIAN STEENSTRUP. 

